Use "auto" with GENERATOR instead of std::function

[folly.git] / folly / Conv.h

diff --git a/folly/Conv.h b/folly/Conv.h
index 22cc8ac470236dec1e48c3d7e6138142837920aa..5a9e0069ab25fba620fc9eafb15549f8b58ed319 100644 (file)
--- a/folly/Conv.h
+++ b/folly/Conv.h
@@ -133,7 +133,7 @@ inline void enforceWhitespace(StringPiece sp) {
     throw makeConversionError(err, sp);
   }
 }
-}
+} // namespace detail
 
 /**
  * The identity conversion function.
@@ -283,7 +283,7 @@ unsafeTelescope128(char * buffer, size_t room, unsigned __int128 x) {
   return p;
 }
 
-}
+} // namespace detail
 #endif
 
 /**
@@ -400,7 +400,7 @@ void toAppend(char value, Tgt * result) {
   *result += value;
 }
 
-template<class T>
+template <class T>
 constexpr typename std::enable_if<
   std::is_same<T, char>::value,
   size_t>::type
@@ -408,6 +408,11 @@ estimateSpaceNeeded(T) {
   return 1;
 }
 
+template <size_t N>
+constexpr size_t estimateSpaceNeeded(const char (&)[N]) {
+  return N;
+}
+
 /**
  * Everything implicitly convertible to const char* gets appended.
  */
@@ -435,12 +440,18 @@ typename std::enable_if<std::is_convertible<Src, const char*>::value, size_t>::
   return 0;
 }
 
-template<class Src>
+template <class Src>
+typename std::enable_if<IsSomeString<Src>::value, size_t>::type
+estimateSpaceNeeded(Src const& value) {
+  return value.size();
+}
+
+template <class Src>
 typename std::enable_if<
-  (std::is_convertible<Src, folly::StringPiece>::value ||
-  IsSomeString<Src>::value) &&
-  !std::is_convertible<Src, const char*>::value,
-  size_t>::type
+    std::is_convertible<Src, folly::StringPiece>::value &&
+        !IsSomeString<Src>::value &&
+        !std::is_convertible<Src, const char*>::value,
+    size_t>::type
 estimateSpaceNeeded(Src value) {
   return folly::StringPiece(value).size();
 }
@@ -450,7 +461,7 @@ inline size_t estimateSpaceNeeded(std::nullptr_t /* value */) {
   return 0;
 }
 
-template<class Src>
+template <class Src>
 typename std::enable_if<
   std::is_pointer<Src>::value &&
   IsSomeString<std::remove_pointer<Src>>::value,
@@ -523,7 +534,7 @@ toAppend(unsigned __int128 value, Tgt * result) {
   result->append(buffer + p, buffer + sizeof(buffer));
 }
 
-template<class T>
+template <class T>
 constexpr typename std::enable_if<
   std::is_same<T, __int128>::value,
   size_t>::type
@@ -531,7 +542,7 @@ estimateSpaceNeeded(T) {
   return detail::digitsEnough<__int128>();
 }
 
-template<class T>
+template <class T>
 constexpr typename std::enable_if<
   std::is_same<T, unsigned __int128>::value,
   size_t>::type
@@ -656,7 +667,7 @@ estimateSpaceNeeded(Src value) {
 namespace detail {
 constexpr int kConvMaxDecimalInShortestLow = -6;
 constexpr int kConvMaxDecimalInShortestHigh = 21;
-} // folly::detail
+} // namespace detail
 
 /** Wrapper around DoubleToStringConverter **/
 template <class Tgt, class Src>
@@ -742,7 +753,7 @@ estimateSpaceNeeded(Src value) {
  * for estimateSpaceNeed for your type, so that we allocate
  * as much as you need instead of the default
  */
-template<class Src>
+template <class Src>
 struct HasLengthEstimator : std::false_type {};
 
 template <class Src>
@@ -776,12 +787,12 @@ size_t estimateSpaceToReserve(size_t sofar, const T& v, const Ts&... vs) {
   return estimateSpaceToReserve(sofar + estimateSpaceNeeded(v), vs...);
 }
 
-template<class...Ts>
+template <class... Ts>
 void reserveInTarget(const Ts&...vs) {
   getLastElement(vs...)->reserve(estimateSpaceToReserve(0, vs...));
 }
 
-template<class Delimiter, class...Ts>
+template <class Delimiter, class... Ts>
 void reserveInTargetDelim(const Delimiter& d, const Ts&...vs) {
   static_assert(sizeof...(vs) >= 2, "Needs at least 2 args");
   size_t fordelim = (sizeof...(vs) - 2) *
@@ -830,8 +841,7 @@ toAppendDelimStrImpl(const Delimiter& delim, const T& v, const Ts&... vs) {
   toAppend(delim, detail::getLastElement(vs...));
   toAppendDelimStrImpl(delim, vs...);
 }
-} // folly::detail
-
+} // namespace detail
 
 /**
  * Variadic conversion to string. Appends each element in turn.
@@ -986,11 +996,12 @@ to(Src value) {
  * toDelim<SomeString>(SomeString str) returns itself.
  */
 template <class Tgt, class Delim, class Src>
-typename std::enable_if<IsSomeString<Tgt>::value &&
-                            std::is_same<Tgt, Src>::value,
-                        Tgt>::type
-toDelim(const Delim& /* delim */, const Src& value) {
-  return value;
+typename std::enable_if<
+    IsSomeString<Tgt>::value &&
+        std::is_same<Tgt, typename std::decay<Src>::type>::value,
+    Tgt>::type
+toDelim(const Delim& /* delim */, Src&& value) {
+  return std::forward<Src>(value);
 }
 
 /**
@@ -1415,8 +1426,9 @@ using ParseToResult = decltype(parseTo(StringPiece{}, std::declval<Tgt&>()));
 struct CheckTrailingSpace {
   Expected<Unit, ConversionCode> operator()(StringPiece sp) const {
     auto e = enforceWhitespaceErr(sp);
-    if (UNLIKELY(e != ConversionCode::SUCCESS))
+    if (UNLIKELY(e != ConversionCode::SUCCESS)) {
       return makeUnexpected(e);
+    }
     return unit;
   }
 };
@@ -1475,6 +1487,14 @@ tryTo(StringPiece src) {
   });
 }
 
+template <class Tgt, class Src>
+inline typename std::enable_if<
+    IsSomeString<Src>::value && !std::is_same<StringPiece, Tgt>::value,
+    Tgt>::type
+to(Src const& src) {
+  return to<Tgt>(StringPiece(src.data(), src.size()));
+}
+
 template <class Tgt>
 inline
     typename std::enable_if<!std::is_same<StringPiece, Tgt>::value, Tgt>::type
@@ -1536,7 +1556,7 @@ tryTo(const Src& value) {
 template <class Tgt, class Src>
 typename std::enable_if<
     std::is_enum<Tgt>::value && !std::is_same<Src, Tgt>::value,
-    Tgt>::type
+    Expected<Tgt, ConversionCode>>::type
 tryTo(const Src& value) {
   using I = typename std::underlying_type<Tgt>::type;
   return tryTo<I>(value).then([](I i) { return static_cast<Tgt>(i); });
@@ -1552,8 +1572,10 @@ to(const Src& value) {
 
 template <class Tgt, class Src>
 typename std::enable_if<
-  std::is_enum<Tgt>::value && !std::is_same<Src, Tgt>::value, Tgt>::type
-to(const Src & value) {
+    !IsSomeString<Src>::value && std::is_enum<Tgt>::value &&
+        !std::is_same<Src, Tgt>::value,
+    Tgt>::type
+to(const Src& value) {
   return static_cast<Tgt>(to<typename std::underlying_type<Tgt>::type>(value));
 }